Conventionally, in order to observe blood or the like by a microscope or the like, a smear preparing apparatus in which blood or the like is dropped on a slide glass and smeared by a spreader glass (smearing member) to generate a smear is used.
Since each sample has different characteristics such as particle density, viscosity and the like, if the smear is always generated under the same condition, the smear becomes unsuitable for observation in some samples.
Therefore, there is known a smear preparing apparatus in which the smearing parameter is set every sample based on a measurement result from a blood analyzer (refer to U.S. Pat. No. 5,209,903).
According to such conventional apparatus, the smearing parameter is determined based on a hematocrit value, for example. In addition, since it is known that blood viscosity is increased as a hemoglobin amount is increased in general, it is considered that the smearing parameter is set based on the measurement result of the hemoglobin amount.
In addition, although the method of setting the smearing parameter by the above conventional apparatus is very effective when the smear is automatically generated, it does not respond to a case of the special sample or various kinds of user's needs.
For example, although the hematocrit value of a leukemia patient is normal or slightly small, it has been found that the WBC (White Blood Cell) of the leukemia patient is weak and liable to be destroyed.
When a blood smear of such patient is made, it is necessary to make it thicker than the smear made under the smearing parameter based on the normal hematocrit value when the blood on the slide glass is smeared by the spreader glass, so as not to destroy the WBC.
In addition, observers who observe the smear by a microscope have different demands for the smear. That is, some observers want to observe thin and spread smear and some observers want to observe the smear thickly collected in a small region.